Gary LaFree, director of START, and Joshua Freilich, START researcher, professor and acting director of the criminal justice program at John Jay College, wrote the introduction for the new issue, explaining how the field is witnessing a huge growth in the depth and sophistication of the criminological research literature on terrorism. They attribute the growth to, among other programs, the expanded funding opportunities with the Department of Homeland Security's Science and Technology Directorate, the National Institute of Justice and the National Science Foundation.

"Research on terrorism arguably represents one of the major growth areas in social science scholarship over the past decade, and quantitative criminological research has figured prominently in these developments," LaFree and Freilich write in the journal's introduction.

While exploring terrorism, all eight of the newly published articles in the journal are within the criminological mainstream in that they each build on methods that originated or are widely applied in criminology. Articles span the geospatial distribution of terrorist "hot spots," sentencing decisions in cases of U.S. terrorist suspects and characteristics of terrorism-related homicides, among other topics.

Among published articles are those from current researchers at START headquarters:

"Patterns of Onset and Decline Among Terrorist Organizations" by Erin Miller, START researchers and project manager for the Global Terrorism Database (GTD). The study uses newly available data from the GTD to analyze the terrorist activity of 557 organizations that were active for at least 365 days between 1970 and 2008. Whereas previous research is focused almost exclusively on the onset of terrorist activities, Miller investigates patterns of decline in organization-level terrorist activity using group-based trajectory models.

Miller's research shows the speed and magnitude of an organization's emergence are correlated with its longevity ? those organizations characterized by rapid onset are two to three times more likely than those characterized by moderate onset to reach moderate or high levels of attacks per year. Likewise, as the rate and overall volume of attacks at onset increase, so does the likelihood that the group will follow a persistent pattern of decline, according to Miller.

"Microcycles of Violence: Evidence from Terrorist Attacks by ETA and the FMLN," by Brandon Behlendorf, START researcher; LaFree; and Richard Legault, START researcher. The research team used the GTD to analyze more than 4,000 terrorist attacks attributed to the FMLN in El Salvador and the ETA in Spain ? two terrorist organizations that were both extremely active and violent but differed greatly in terms of history, grievances and motives. While recent research has demonstrated that individual crimes elevate the risk for subsequent crimes nearby ? a phenomenon termed "near-repeats" ? those assessments only reveal global patterns of event interdependence, ignoring the possibility that individual events may be part of localized bursts of activity ? "microcycles."

In the new study, the researchers find strong support for the conclusion that many of the terrorist attacks attributed to these two distinctive groups were part of violent microcycles and that the spatio-temporal attack patterns of these two groups exhibit substantial similarities. With both ETA and the FMLN, bombings and non-lethal attacks are more likely to be part of microcycles when compared with other tactics used by terrorists. They also show that attacks aimed at national or provincial capitals or areas of specific strategic interest to the terrorist organization are more likely to be part of microcycles, and for the FMLN only, compared to other attacks, those on military and government targets were more likely part of microcycles.

"Spatial and Temporal Patterns of Terrorist Attacks by ETA 1970 to 2007" by LaFree; Laura Dugan, START researcher and associate professor of criminology and criminal justice at the University of Maryland; Min Xi from Arizona State University; and Piyusha Singh, from Excelsior College. In this article, the researchers examine spatial and temporal patterns of terrorist attacks by ETA to investigate how seemingly irrational behavior on the part of a terrorist organization might reflect strategic planning. The new analysis is guided by the public announcement made by ETA in 1978 that the group would shift from emphasizing attacks in the Basque territory to launching attacks more widely in the hopes of exhausting the Spanish government and forcing it to abandon the Basque territory.

The researcher team found that after ETA moved toward a more attrition based attack strategy, subsequent attacks were significantly more likely to occur outside the Basque region and to target non-adjacent regions and spread to more distant locations (hierarchical diffusions). They also show how hierarchical diffusion was more common when a longer time elapsed between attacks and that attacks against Madrid were unlikely to be followed immediately by more attacks on Madrid or surrounding provinces. The researchers conclude that after ETA announced a shift in policy, they maintained a highly dispersed attack strategy even during their period of decline.

For a complete list of articles in this special issue of the Journal of Quantitative Criminology, click here.